/Engine/Source/Runtime/GeometryCore/Public/DynamicMesh/DynamicMesh3.h
Get triangle one-ring at vertex.
[EMeshResult](API\Runtime\GeometryCore\UE__Geometry__EMeshResult) GetVtxTriangles ( int VertexID, [TArray](API\Runtime\Core\Containers\TArray)< int > & TrianglesOut ) const